27. A dominant gene controlling accumulation of glucomannan in the cell wall of rice endosperm

M. YANO1, R. ZAMORSKI2, A. SAITO3 and N. SHIBUYA4

1) Hokuriku National Agricultural Experiment Station, Inada, Joetsu, Niigata, 943-01 Japan
2) Technical Agricultural University, Bydgoszcz, Poland
3) Department of Molecular Biology, National Institute of Agrobiological Resources, Tsukuba, 305 Japan
4) Department of Cell Biology, National Institute of Agrobiological Resources, Tsukuba, 305 Japan

Although the cell wall plays an important roll for growth, differentiation and physical properties of cells and tissues in plants, a few work have been reported concerning genetic regulation of its chemical components. Recently, varietal differences of the chemical component in the cell wall of rice endosperm have been revealed (Zamorski et al. unpublished data). Among several polysaccharides in endosperm cell wall, the amount of glucomannan constantly occupied about 10% of the total in Indica and some Japonica varieties, although it was undetectable in some Japonica varieties. In the present study, we have carried out linkage analysis of the gene controlling the accumulation of glucomannan in the endosperm cell wall using RFLP markers.

An F1 plant between Indica, Kasalath (glucomannan positive) and a Japonica, Nipponbare (glucomannan negative) was backcrossed with Nipponbare, and the resultant BC1 population was used in this study. About 100 self-pollinated seeds derived from the 69 BC1 plants were chemically analyzed to identify glucomannan accumulation. As the result, the 69 BC1 individuals were classified into two groups, 31 glucomannan positive and 38 negative. The segregation ratio fitted the 1:1 ratio (X2 = 0.71). This result indicates that the accumulation of glucomannan is controlled by a single dominant gene. We tentatively designate the gene as Man (mannan in endosperm cell wall).

Linkage analysis of Man with 50 RFLP markers randomly selected from the RFLP linkage map (Saito et al. 1991) showed that gene, Man was linked to RFLP markers Xnpb13, Xnpb108 and Xnpb293 on chromosome 9. Accordingly, the gene, Man was mapped on the 4.3 cM distal point to Xnpb293, which is the most distal marker of chromosome 9 (Fig. 1).

References

Saito, A., M. Yano, N. Kishimoto, M. Nakagahra, A. Yoshimura, K. Saito, S. Kuhara, Y. Ukai, M. Kawase, T. Nagamine, S. Yoshimura, O. Ideta, R. Ohsawa, Y. Hayano, N. Iwata and M. Sugiura, 1991. Linkage map of restriction fragment length polymorphism loci in rice. Japan. J. Breed. 41: 665-670.